London -LRB- CNN -RRB- -- London 's Heathrow Airport is `` fully operational '' and returning to normal after an emergency landing Friday forced the closing of both runways , the airport said -- but many travelers are likely to suffer delays anyway .

British Airways has canceled all its inbound and outbound short-haul flights until 4 p.m. -LRB- 11 a.m. ET -RRB- as a result of the incident .

And Heathrow Airport has warned of disruption to travel that could last all day .

So far , 23 planes have been diverted to other airports and 19 flights canceled , some arrivals and some departures , a spokeswoman said Friday morning .

The airport is working to return to normal service as soon as possible , she said , but passengers are advised to check with their airlines .

A British Airways plane bound for Oslo was forced to make the emergency landing `` due to a technical fault , '' the airline said .

Flight BA762 turned back less than half an hour after taking off for the Norwegian capital , it said .

The Airbus A319 aircraft was carrying 75 passengers and five crew members , the airline said . The passengers were evacuated from the plane on emergency slides .

`` Airline colleagues are now caring for customers in the airport terminal , '' said British Airways .

London Ambulance Service treated three patients for minor injuries after the emergency landing , it said on Twitter .

British Airways said it would be carrying out a full investigation into the incident , alongside the Air Accident Investigation Branch , part of the UK Department for Transport .

The slides were deployed on the left side of the aircraft , indicating that the problem was with the right engine , said CNN 's Richard Quest .

Planes can fly safely even if only one engine is operational , he said .

London Fire Brigade said one of its crews helped the airport fire service put out an aircraft fire . `` We believe the fire is now out , '' it said via Twitter .

Heathrow , which is a major international hub , was ranked the third busiest airport in the world in 2012 after Atlanta and Beijing , according to Airports Council International .

Monday is a holiday in the United Kingdom , so many people will be taking flights Friday to take advantage of the long weekend .

Holidaymaker Aileen Wilson was one of many travelers whose flight was grounded by the incident .

`` We 've just been sitting , waiting in a plane meant to take off '' this morning , she told CNN iReport . `` At first we were told ongoing incident and then emergency landing . We -LRB- are -RRB- still waiting to take off -LRB- and -RRB- not allowed out of plane ! ''

Instagram user Shazia Shaikh took a photograph from the office where she works at Heathrow Airport of emergency vehicles surrounding a plane .

`` Runways closed -LRB- and -RRB- lots of smoke , '' she told CNN iReport . `` The rain does n't help . Emergency vehicles were quick to the aircraft I 'm told . ''

On average , 190,000 passengers travel through the airport each day , half arriving and half departing , according to Heathrow 's website .

CNN 's Claudia Rebaza , Richard Allen Greene , Sarah Brown and Dominique Van Heerden contributed to this report .

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NEW : British Airways cancels all its short-haul flights through Heathrow until 4 p.m.

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Heathrow : The airport is `` fully operational '' and returning to normal after runway closures

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British Airways says a plane bound for Oslo had to turn back because of a technical fault

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The Airbus A319 aircraft was carrying 75 passengers ; 3 were treated for minor injuries